BITING MIDGES — WIRTH AND BLANTON 459 



readily in pinned mounts by the greater development of the dark 

 mesonotal striae, and the much hairier wing on which the dark color 

 pattern is more extensive. On the wing there is a dark mark extend- 

 ing from the base of the second radial cell almost to its apex and 

 extending over into cell R5 as a small rounded dark spot just behind 

 the tip of the second radial cell. In some specimens the latter dark 

 spot is narrowly connected to the next distal dark area as figured by 

 Fox for caprilesi. C. almirantei, new species, is also closely related, 

 having the second radial cell entirely dark, but it can be separated 

 from caprilesi by its long distal antennal segments (antennal ratio, 

 1.25) and shorter costa (to 0.69 of wing length). 



83. Culicoides pachymerus Lutz 



Figure 86 



Culicoides pachymerus Lutz, 1914, Mem. Inst. Oswaldo Cruz, vol. 6, p. 83 (female; 

 Rio Negro, Brazil; fig. wing, leg). — Costa Lima, 1937, idem., vol. 32, p. 421 

 (unrecognizable). — Wirth, 1955, Proc. Ent. Soc. Washington, vol. 57, p. 112 

 (questionable identification, descriptive notes; Guatemala; fig. palpus). 



Female: Length of wing 0.72 (0.67-b.76, n=7) mm. 



Head. — Eyes very broadly separated, bare. Antenna with flagellar 

 segments in proportion of 16:13:13:14:14:14:14:14:14:13:14:13:22, 

 antennal ratio 0.66 (0.62-0.71, n = 5); distal sensory tufts present on 

 segments in, ix and x, rarely on viii. Palpal segments in proportion 

 of 5:11:18:6:10, third segment very slightly swollen, 1.8 (1.6-2.1, 

 n=7) times as long as greatest breadth, with a small, shallow sensory 

 pit. Mandible with 14 (11-18, n=8) teeth. 



Thorax. — Mesonotum and scutellum uniform tawny yellowish 

 brown, with vestiture of short appressed yellowish hairs. Post- 

 scutellum and pleuron brownish. Legs yellowish, femora and tibia 

 with very faint, broad, median brownish bands; hind tibial comb 

 with four (n = 6) spines, the one nearest the spur longest; legs stout, 

 fore and hind femora greatly swollen, fusiform, slightly flattened 

 laterally. 



Wing. — Pattern as figured; pale spot over r-m crossvein large and 

 broadly meeting costal wing margin; poststigmatic pale spot in cell 

 R5 including distal half of vein R4+5, the extremely long and narrow 

 second radial cell thus appearing pale on distal half; the poststigmatic 

 pale spot narrow in cell R5 distal to end of costa, extending obliquely 

 proximad and greatly broadened posteriorly to vein Mi behind second 

 radial cell; distal pale spot in cell R5 varying in extent, usually oval 

 in shape and not attaining wing margin, but in some specimens with 

 a narrow anterior extension extending distad to wing tip; two elon- 

 gated pale spots in cell Mi; two pale spots in distal portion of cell 

 M2; pale spot in cell M4 nearly filling cell; anal cell with large pale 



